1. Field of the Invention.
This invention generally relates to weighing systems, and more particularly to an electronic scale and a system and method which uses the electronic scale to compute postal and private carrier rates for letters, packages, parcels, and other items of mail.
2. Description of the Related Art.
Even with E-mail and other forms of electronic data transfer which are so prevalent today, traditional mail, either through the U.S. Postal Service or by private carrier, remains the dominant form of information exchange. In order to successfully send an item through the mail, correct postage must, of course, be computed. To determine postage, a number of factors must be taken into consideration, not the least of which include the class, destination, and weight of the item being sent. At least three methods are currently in use for determining the weight of mail, and as will be apparent below all of them fall short of being optimum.
The traditional method of weighing mail involves using an analog scale. According to this method, a letter is weighed on the scale and postage is then determined by comparing the scale measurement to a rate table issued by a mail carrier. This method has proven to be inefficient, especially for businesses, because it is an entirely manual process. To mail a letter, for example, a secretary is often required to go to a mail room to access the scale and rate tables. In other instances, the scale is kept at the secretary""s desk, making a trip to the mail room unnecessary. Even under these circumstances, however, the process is inefficient because keeping the scale on the secretary""s desk reduces her usable work space. Either way, the traditional method of computing postage is inefficient.
An improved method of computing postage involves using an electronic, programmable postal meter. Electronic postal meters are highly favored by businesses because they essentially automate the mailing process. While meters of this type come in varying sizes, from small stand-alone units to full-size systems capable of weighing packages of varying weights and sizes, all have the same basic features: a keyboard for entering rate data into a meter memory, an electronic scale, and a processor for computing postage based on the stored rate data and weight measurements taken by the scale. U.S. Pat. Nos. 5,724,245, 5,615,120, 4,814,995, and D 305,103 disclose meters of this type.
In spite of their advantages, electronic postal meters have at least three drawbacks. First, postal meters cannot be bought but only rented for a fee. These rental fees contribute to operating expenses, and sometimes significantly depending upon the size of the renter.
Second, electronic postal meters require considerable maintenance because, one, the scales connected to the meters must be manually adjusted every time new postal rates are issued and, two, the meters must be periodically inspected, serviced, and replaced, often at additional expense to the renter.
Third, most electronic postal meters in use today are of a size which, in practical terms, are unsuitable for use on a worker""s desk. Consequently, postal meters are almost universally kept in mail rooms and thus have associated with them many of the inefficiencies attendant to analog scales.
A further improved method of computing postage borrows from the power of the personal computer. This method eliminates the need for electronic postal meters because the functions performed by the meter processor are replaced by a CPU running a postal computation program. Computer programs of this type, exemplified by U.S. Pat. No. 5,606,507 to Kara, are typically Windows-type programs which automatically compute postage based on weight measurements taken by an electronic scale connected to a communications port of the computer. Once postage has been computed, the program instructs a peripheral device to print an envelope or label bearing a stamp of appropriate value.
Use of a personal computer to compute postage represents a significant improvement in the art. Through the computer, a secretary can, for example, perform all mailing responsibilities at her desk, thereby streamlining the mailing process. Further, through a convenient and easily understandable graphic user interface, novices can in no time learn to use the postal program with a proficiency equal to that of trained personnel. Also, because postal programs can be purchased, they do not represent a continuing economic burden on the businesses which use them.
For all of their advantages, software-based mailing systems are not optimum because they are not fully integrated. Perhaps most significantly, while the processing functions of the electronic postal meter have been incorporated into the personal computer, its hardware components have not. This is exemplified by systems like Kara, discussed above, which must still use an electronic scale separate from the computer to obtain the weight measurements required for computing postage. Use of a separate scale is inefficient because, like an analog scale, it consumes desk space which could be put to more productive use.
A need therefore exists for a system for computing postal and carrier rates which is integrated so that desk space is not unnecessarily consumed and which therefore is more convenient and efficient compared with postage-computing systems presently in use.
It is one object of the present invention to provide a system for computing postage and/or private carrier rates which is more efficient than those presently in use.
It is another object of the present invention to achieve the above object by providing an electronic scale cartridge which is adapted for removable connection to a piece of office equipment, so that all elements for computing rates are conveniently located at a user""s work area, thereby streamlining the mailing process and increasing the effective work space of an individual in a home or business environment.
It is another object of the present invention to provide an electronic scale cartridge which is adapted for removable connection to a portable electronic device such as a personal digital assistant, wireless communications device, or other hand-held or transportable system equipped with computing capability, thereby enabling a user to determine postal and/or carrier rates when on travel or otherwise away from the office.
It is another object of the present invention to provide an electronic scale cartridge which has a connector that fits a universal or standard port or signal format, thereby allowing the invention to interface to any number of devices without modification.
It is another object of the present invention to provide a software-driven system and method which computes postal and/or carrier rates based on weight signals derived from the aforementioned type of electronic scale.
It is another object of the present invention to provide an electronic scale which is adapted for connection to a piece of equipment, which connection is preferably rotatable to allow a user to move the scale into an optimum position for weighing.
It is another object of the present invention to provide an electronic scale having a housing which is adapted for removable connection to a piece of office equipment.
It is another object of the present invention to provide a docking station which is adapted to receive the electronic scale cartridge of the present invention and which also has a surface for supporting a piece of office equipment, which docking station thereby increases integration of elements required to compute postage in accordance with the software-driven system and method of the present invention.
The foregoing and other objects of the invention are achieved by providing an electronic scale cartridge which plugs into a piece of office equipment and/or a portable electronic device. The scale cartridge includes a platform for supporting an item of mail, a weighing unit having a force transducer which outputs a signal indicative a weight of the item, and an electrical connector which removably mates with a complementary connector in the piece of office equipment and/or portable electronic device. In operation, the scale connector outputs the weight signal from the force transducer into the complementary connector of the piece of office equipment or portable electronic device. The weight signal is then passed to a display for viewing and/or to a processor which computes a corresponding postal or private carrier rate.
For convenience of use, the scale cartridge may be removed simply by pulling it from the complementary connector. Because the cartridge is easily removable, it may be upgraded or downgraded to suit the needs of the user. For example, the cartridge may be adapted to be interchangeable with cartridges of different load cell capacities. Further, the removable connection allows damaged or defective cartridges to be easily replaced.
The weighing unit may be any type capable of meeting the size requirements of the cartridge housing. For example, the weighing unit has none or a limited number of moving parts, and the force transducer may be of any type conventionally known including but not limited to load cells, strain gauges, and piezeoelectric or piezoresistive elements. Also, the housing of the cartridge may be horizontally or vertically oriented to suit, for example, the space requirements of a user""s work area.
In one embodiment, the weighing unit includes two support members for supporting the platform and a force transducer mounted at a position underneath the platform. When an item of mail is placed on the scale, the scale platform applies a force against the force transducer and a weight signal is output. The support member may be spring loaded for enhanced stability, and a stub may be included on a lower surface of the platform to transfer the weight of the item to the force transducer.
In another embodiment, the platform applies a force directly against the force transducer when an item of mail is placed on the platform. This may be achieved, for example, by connecting the platform to the force transducer by screws or another form of attachment. Alternatively, the platform may be sized to be slightly greater than the housing of the cartridge so that the housing provides horizontal stability, thereby leaving the platform rest by force of gravity against the force transducer. The weighing unit of this embodiment, thus, effectively has no moving parts.
In another embodiment, the platform has a stub on its lower surface that applies a force against the force transducer, which may or may not be connected to the stub. In this arrangement, the stub may be connected to the force transducer, or alternatively the housing of the cartridge may provide the horizontal stability required to allow the stub to rest by force of gravity against the force transducer. This embodiment also effectively has no moving parts.
In another embodiment, the platform dimensions may be smaller than the housing so that the housing walls provide the horizontal stability to the platform during weighing. To allow the weight of a mail item to be accurately transferred to the force transducer, the platform may be raised in relation to the housing walls, but in a way that still provide direct contact between the lower surface of the platform and the load cell.
In another embodiment, the weighing unit includes a support member in the form of a pivot arm having a first end in contact with the platform and a second end rotatably mounted to a surface within the cartridge housing. In operation, the arm pivots to apply a force against the force transducer which corresponds to the weight of an item placed on the platform.
In another embodiment, the scale cartridge may have a housing adapted for insertion into a slot formed in the piece of office equipment (e.g., a computer or one of its peripheral or input devices) or portable electronic device (e.g., a personal digital assistant or wireless communications device equipped with computing capability). The housing may have a horizontal orientation or a vertical orientation.
A number of optional features may be included on each of the embodiments of the scale cartridge of the present invention. For example, a printed circuit board may be included in the cartridge housing for converting the weight signal to a format compatible with any number of signal standards. Alternatively, the force transducer may output the weight signal directly. Also, the platform of the scale may be removably mounted to the weighing unit to allow other platforms of different shapes or dimensions to be connected.
The system of the present invention advantageously uses the removable scale cartridge to compute postal/private carrier rates in accordance with a program stored in a personal computer or electronic device. If desired, the program may be obtained from an application service provider through a network connection. In operation, the program computes these rates based on weight measurement signals derived from the scale, as well as other mailing parameters entered, for example, by keyboard or mouse.
The method of the present invention is implemented in accordance with the system described above. According to this method, postal/carrier rate information is loaded into the computer or device manually, from a disk, or from a network such as the Internet. A postal program is then initiated, for example, by clicking an icon on the computer or device screen or merely by placing an item to be weighed on the scale. The program may have been previously stored in a memory of the computer or device, or may be accessed from an application service provider or other client-server source. Once initiated, the program computes a rate based on a weight measurement signal from the scale and/or class, zone, and other parameters entered by the user or pre-programmed into the system. If desired, the program may be written so that these parameters are entered in response to requests sequentially displayed on the computer screen. A label or envelope bearing a mark corresponding to the postal rate is then printed either by a peripheral connected to the computer or device or by a printer integrated in the computer or device.
The present invention is also an electronic scale which is adapted for attachment to a piece of equipment. This embodiment of the scale includes a housing, a platform for supporting an item of mail, a weighing unit mounted at least partially within the housing and having a force transducer which outputs a weight signal corresponding to a weight of the item supported on the platform, and a fastener which fastens the housing of said scale to a piece of equipment. The fastener may one which removably and/or rotatably attaches the scale to the piece of equipment. The rotatable attachment is especially advantageous because it allows a user to adjust the scale to a level position regardless of the inclination of the equipment surface to which it is attached. In one embodiment, the fastener includes snap members. In other embodiment, the fastener is a magnet. In still other embodiments, the fastener takes the form of a removable pin, a screw, an adhesive, a clip which is preferably spring biased for enhanced stability, and even a velcro arrangement.
Finally, the present invention is a weighing arrangement that includes any one of the scale cartridges previously described which is adapted for insertion into a docking station. To provide enhanced office integration, the docking station may have a surface for supporting a piece of equipment, as well as a slot having a complementary connector adapted for coupling to the scale cartridge.